The present invention relates to an implantable apparatus for use treating gastroesophageal acid reflux and particularly to an artificial sphincter for the lower esophageal sphincter.
Gastroesophageal reflux disease (GERD) is one of the most common medical illnesses in today""s western society. Gastroesophageal reflux occurs when the contents of the stomach, including acids and digestive fluids, leak back past the lower esophageal sphincter into the esophagus. This produces the sensation commonly referred to as xe2x80x9cheartburnxe2x80x9d. Over prolonged periods, this condition can seriously compromise a person""s health. Studies indicate that the incidence of gastroesophageal reflux is on the rise. For example, health care providers use Common Procedural Terminology (xe2x80x9cCPTxe2x80x9d) codes to report treatment of certain conditions. In 1999, the CPT code for GERD was the most commonly used code from gastroenterologists"" offices in the United States, indicating the prevalence of the condition. Incidence of this disease is similarly common in all parts of Europe and probably in any affluent society.
Currently, there are four options available for treatment of gastroesophageal reflux disease. These options are life-style modification, medication, surgery, and endoscopic fundoplication. Life-style modification comprises dietary changes and positioning of body so that, with the help of gravity, upward reflux of food and acid from the stomach is prevented. This treatment is seldom effective alone.
Medication is the most common treatment. Depending upon the degree of severity, a physician may prescribe medications ranging from less potent acid-blockers like Ranitidine (the so-called xe2x80x9cHistamine 2 receptor blockerxe2x80x9d) to strong acid-production blockers like Prilosec (the Proton pump inhibitorsxe2x80x94PPI). The results from treatment by medication are quite satisfactory in the majority of the cases. The problems are the need to take medication for the remainder of the patient""s life with its enormous cost, the inconvenience of constantly keeping medicine with the patient, and the long-term concern about strong acid inhibition as a side effect of the medication. There is some data suggesting that atrophic gastritis may develop in some patients as a result of longterm therapy by medication. There is also a phenomenon called acid-rebound after discontinuation of medication. Finally, although medical therapy is effective against acid reflux conditions, it is not effective in controlling so-called xe2x80x9calkalinexe2x80x9d or xe2x80x9cbilexe2x80x9d reflux.
Surgical therapy is currently recommended for the patients whose symptoms are not controlled by medication or for the patients who do not want to take long-term medication. Both traditional surgical procedures and laparoscopic approaches have been tried. Recent literature suggests that there may be significant long-term concerns with regard to the laparoscopic approach. Of course, the patient has to be physically fit to undergo such a procedure. In spite of cost, the difficulty of patient selection and the invasiveness involved, approximately 80,000 of these procedures were performed in the United States in 1999.
Endoscopic fundoplication is a very recent procedure done by the gastroenterologists. It consists of securing a suture in a purse-string-like configuration to the part lower part of the esophagus or upper part of the stomach, which basically creates an additional mechanical barrier to the contents of reflux from the stomach to esophagus. The data is very preliminary on this procedure and very few gastroenterologists are trained to perform it. Even in the best case, there are significant limitations to the procedure and some patients with large hiatus hernia will not qualify for this.
Despite multiple treatment options, treatment of GERD still needs improvement in long-term, low-cost treatment. Therefore, there is room for improvement in this area. I plan to accomplish this by an implantable esophageal sphincter apparatus, described below.
The apparatus comprises an adjustable band or sphincter body to be placed at the lower part of esophagus, most of the time over or around the Lower Esophageal Sphincter (LES) or around the very first part of stomach adjoining the esophagus. The internal inflation of the band can be increased or decreased to some extent, which in turn will adjust the tightness of the device. This will meet the need for some patients who might find it easier to swallow with a loose band and subsequently make it tighter to prevent reflux. The device will be of human-grade implantable material. The device will enhance the normal tone or pressure of the LES that naturally exists in the competent LES. In many cases, this natural tone is lost or these patients have more frequent LES relaxation than normal. This leads to chronic GERD. Placement of the esophageal band will prevent these phenomena from occurring and thereby prevent GERD. In short, this will mimic the normal human physiology by a mechanical means. This will promote the natural pressure barrier between the esophagus and stomach that naturally exists in normal physiologic state. The end result will be prevention of reflux and thereby GERD.
The apparatus will be implanted in a single surgical procedure. Most of the time, it could be placed by laparoscopic methods, which will minimize the invasiveness of the surgery and will lessen the duration of hospitalization. In some situations, a traditional open surgical method may be required. After gaining access in the abdominal or thoracic cavity either by laparoscopic or open surgical technique, the surgeon will isolate the area of the lower esophageal sphincter and the esophago-gastric junction (EGJ). During this procedure, an endoscope or a bougie of a satisfactory diameter placed per orally will give both guidance to the degree of tightness and protection to the esophagus. An inflatable sphincter body may be wrapped around the esophagus and may be connected to an inflation device with a fluid reservoir. The inflation device and reservoir may be implanted underneath the skin of the anterior chest wall or of the abdominal wall during the same surgical procedure with the sphincter body. The inflation device may have a pump mechanism that will respond to external control to increase or decrease the inflation of the sphincter body that, in turn, will either increase or decrease the tightness of the area upon which the sphincter body is placed (usually at the lower esophageal sphincter). The sphincter body may be held in place at the area of implantation by sutures and by fenestration mechanisms, which will allow ingrowths of tissue or fibrous elements of the body around the sphincter body or into porous materials on the sphincter body. After placement of the full device, the physician or surgeon will activate the pump mechanism and test the response of the mechanism before final closure.
The apparatus may also include a circumferential shield on a distal side of the sphincter body. The shield is adapted to fit against the distal or lower side of the patient""s diaphragm and inhibits the development or re-occurrence of a hiatus hernia, that is, a protrusion of the stomach past the diaphragm through the passage for the esophagus. The apparatus, therefore, also provides a treatment for hiatus hernias.
A patient would undergo normal pre-surgical evaluation to determine suitability as a surgical candidate. Both gastroenterologists and surgeons with appropriate interests and competency in reflux treatment procedures should usually be consulted. Tests may include upper gastrointestinal endoscopy, and 24-hour pH and motility testing. These tests would provide objective evidence of GERD in the patient involved, including evidence of severity of damage, anatomic integrity of the organs involved, associated co-existing diseases that can effect patient""s outcome and the extent and severity of reflux itself. In addition, certain radiological testing to image the upper gastrointestinal organs may also be an integral part of this evaluation.
After implantation of the apparatus, a physical examination of the patient may be conducted to reevaluate signs and symptoms as they pertain to the patient""s pre-surgical and post-surgical outcome. If appropriate, endoscopy, 24-hour pH and motility studies may also be included in the post-surgical testing. Certain radiological testing, such as a CT scan, or upper gastrointestinal radiology, may be included.
It is an object of my invention, therefore, to provide an apparatus for the treatment of gastroesophageal reflux disease. Another object of my invention is to provide an apparatus having a prosthetic sphincter body for placement at or near the lower esophageal sphincter.
Yet another object of my invention is to provide a sphincter body that is inflatable to predetermined size.
Another object of my invention is to provide an artificial sphincter body that cannot be closed beyond a predetermined minimum orifice size. A further object of my invention is to provide control mechanisms for controlling the size of the sphincter body.
Another object of my invention is to provide an artificial sphincter body for the esophagus with a gap or opening to allow the sphincter body to be placed around the esophagus.
It is also an object of my invention to provide an implantable prosthetic sphincter having a shield to prevent development or re-occurrence of hiatus hernias of the stomach through the diaphragm.
These and other features and advantages of the present invention will be apparent to one skilled in the art from the following detailed description, connection with the accompanying drawings.